PRINCIPLES OF SUTURE SELECTION
The surgeon has a choice of suture materials from which to select for use in body tissues. Adequate strength of the suture material will prevent suture breakage. Secure knots will prevent knot slippage. But the surgeon must understand the nature of the suture material, the biologic forces in the healing wound, and the interaction of the suture and the tissues. The following principles should guide the surgeon in suture selection.
1.WHEN A WOUND HAS REACHED MAXIMAL STRENGTH, SUTURES ARE NO LONGER NEEDED. THEREFORE:
a.Tissues that ordinarily heal slowly, such as fascia and tendons, should usually be closed with nonabsorbable sutures. An absorbable suture with extended (up to 6 months) wound support may also be used.
b.Tissues that heal rapidly, such as stomach, colon, and bladder, may be closed with absorbable sutures.
2.FOREIGN BODIES IN POTENTIALLY CONTAMINATED TISSUES MAY CONVERT CONTAMINATION TO INFECTION. THEREFORE:
a.Avoid multifilament sutures which may convert a contaminated wound into an infected one.
b.Use monofilament or absorbable sutures in potentially contaminated tissues.
3.WHERE COSMETIC RESULTS ARE IMPORTANT, CLOSE AND PROLONGED APPOSITION OF WOUNDS AND AVOIDANCE OF IRRITANTS WILL PRODUCE THE BEST RESULT. THEREFORE:
a.Use the smallest inert monofilament suture materials such as nylon or polypropylene.
b.Avoid skin sutures and close subcuticularly, whenever possible.
c.Under certain circumstances, to secure close apposition of skin edges, a topical skin adhesive such as DERMABOND* Topical Skin Adhesive, or skin closure tape such as PROXI-STRIP* Skin Closures, may be used.
4.FOREIGN BODIES IN THE PRESENCE OF FLUIDS CONTAINING HIGH CONCENTRATIONS OF CRYSTALLOIDS MAY ACT AS A NIDUS FOR PRECIPITATION AND STONE FORMATION. THEREFORE:
a.In the urinary and biliary tract, use rapidly absorbed sutures.
5.REGARDING SUTURE SIZE:
a.Use the finest size, commensurate with the natural strength of the tissue.
b.If the postoperative course of the patient may produce sudden strains on the suture line, reinforce it with retention sutures. Remove them as soon as the patient’s condition is stabilized.
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METRIC MEASURES AND USP SUTURE DIAMETER EQUIVALENTS
USP Size |
11-0 |
10-0 9-0 |
8-0 7-0 |
6-0 |
5-0 4-0 |
3-0 2-0 |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
||||
Natural Collagen |
– |
0.2 |
0.3 |
0.5 |
0.7 |
1.0 |
1.5 |
2.0 |
3.0 |
3.5 |
4.0 |
5.0 |
6.0 |
7.0 |
8.0 |
– |
– |
Synthetic Absorbables |
– |
0.2 |
0.3 |
0.4 |
0.5 |
0.7 |
1.0 |
1.5 |
2.0 |
3.0 |
3.5 |
4.0 |
5.0 |
6.0 |
6.0 |
7.0 |
– |
Nonabsorbable Materials |
0.1 |
0.2 |
0.3 |
0.4 |
0.5 |
0.7 |
1.0 |
1.5 |
2.0 |
3.0 |
3.5 |
4.0 |
5.0 |
6.0 |
6.0 |
7.0 |
8.0 |
SURGICAL NEEDLES
Necessary for the placement of sutures in tissue, surgical needles must be designed to carry suture material through tissue with minimal trauma. They must be sharp enough to penetrate tissue with minimal resistance. They should be rigid enough to resist bending, yet flexible enough to bend before breaking. They must be sterile and corrosion-resistant to prevent introduction of microorganisms or foreign bodies into the wound.
To meet these requirements, the best surgical needles are made of high quality stainless steel, a noncorrosive material. Surgical needles made of carbon steel may corrode, leaving pits that can harbor microorganisms. All ETHICON* stainless steel needles are heat-treated to give them the maximum possible strength and ductility to perform satisfactorily in the body tissues for which they are designed. ETHALLOY* needle alloy, a noncorrosive material, was developed for unsurpassed strength and ductility in precision needles used in cardiovascular, ophthalmic, plastic, and microsurgical procedures.
Ductility is the ability of the needle to bend to a given angle under a given amount of pressure, called load, without breaking. If too great a force is applied to a needle it may break, but a ductile needle will bend before breaking. If a surgeon feels a needle bending, this is a signal that excessive force is being applied. The strength of a needle is determined in the laboratory by bending the needle 90˚; the required force is a measurement of the strength of the needle. If a
needle is weak, it will bend too easily and can compromise the surgeon’s control and damage surrounding tissue during the procedure.
Regardless of ultimate intended use, all surgical needles have three basic components: the attachment end, the body, and the point.
The majority of sutures used today have appropriate needles attached by the manufacturer. Swaged sutures join the needle and suture together as a continuous unit that is convenient to use and minimizes tissue trauma. ATRALOC* surgical needles, which are permanently swaged to the suture strand, are supplied in a variety of sizes, shapes, and strengths. Some incorporate the CONTROL RELEASE* needle suture principle which facilitates fast separation of the needle from the suture when desired by the surgeon. Even though the suture is securely fastened to the needle, a slight, straight tug on the needleholder will release it. This feature allows rapid placement of many sutures, as in interrupted suture techniques.
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The body, or shaft, of a needle is the portion which is grasped by the needleholder during the surgical procedure. The body should
be as close as possible to the diameter of the suture material. The curvature of the body may be straight, half-curved, curved, or compound-curved. The cross-sectional configuration of the body may be round, oval, side-flattened rectangular, triangular, or trapezoidal. The oval, side-flattened rectangular, and triangular shapes may be fabricated with longitudinal ribs on the inside
or outside surfaces. This feature provides greater stability of the needle in the needleholder.
The point extends from the extreme tip of the needle to the maximum cross-section of the body. The basic needle points are cutting, tapered, or blunt. Each needle point is designed and produced to the required degree of sharpness to smoothly penetrate the types of tissue to be sutured.
Surgical needles vary in size and wire gauge. The diameter is the gauge or thickness of the needle wire. This varies from 30 microns (.001 inch) to 56 mil (.045 inch, 1.4 mm). Very small needles
of fine gauge wire are needed for microsurgery. Large, heavy gauge needles are used to penetrate the sternum and to place retention sutures in the abdominal wall. A broad spectrum of sizes are available between these two extremes.
Of the many types available, the specific needle selected for use is determined by the type of tissue to be sutured, the location and accessibility, size of the suture material, and the surgeon’s preference.